ELDORADO, Texas (CNN) -- Ambulances rolled into a Texas ranch that's home to members of a polygamist sect, as authorities continued their search Saturday night for possible victims of physical and sexual abuse.

Authorities are seeking Dale Barlow, 50, seen in a mugshot from a 2005 arrest on child sex charges.

The emergency vehicles were called for as investigators prepared to search the group's temple, law enforcement officials said.

The sect is a rogue branch of the Mormon church, which forbids nonbelievers from entering its temples.

Authorities wanted medical backup "in case they're involved in sensitive areas that could escalate into a negative reaction," a law enforcement source said.

A police helicopter also had begun circling the ranch Saturday night.

Earlier, dozens more children and young women were removed from the compound.

A total of 183 people, including 137 children, have been taken away since law enforcement officers raided the compound Thursday night, said Marleigh Meisner, a spokeswoman for the Texas Child Protective Services Division.

The children -- most of them girls -- were being interviewed by special investigators, she said.

"We're trying to find out if they're safe," she explained. "We need to know if they have been abused or neglected."

Eighteen of the girls have been taken into state custody.

Authorities believe that they "had been abused or were at immediate risk of future abuse," said Child Protective Services spokesman Darrell Azar.

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Law enforcement agencies raided the ranch Thursday night after receiving a report Monday that a 16-year-old girl had been "sexually and physically abused," Azar said.Watch buses take girls from compound »

The warrant cited an "immediate need" for authorities to have access to the 16-year-old and an 8-month-old child with either the last name of Barlow or the girl's last name. It instructs law enforcement officers to look for any records showing that Barlow and the girl were married and any evidence of them having a child.

Barlow is in Arizona and does not know his accuser, his probation officer told The Salt Lake Tribune.

"He said the authorities had called him [in Colorado City, Arizona], and some girl had accused him of assaulting her, and he didn't even know who she was," Bill Loader said.

Barlow pleaded no contest last year to conspiracy to commit sexual conduct with a minor, The Associated Press reported.

He was ordered to register as a sex offender for three years, according to the AP.

His lawyer in that case told the AP he had not spoken to Barlow in a year.

Jeffs,the 52-year-old leader and "prophet" of the 10,000-member church, was convicted in Utah last year and sentenced to 10 years on two counts of being an accomplice to rape, charges related to a marriage he performed in 2001. He faces trial in Arizona on eight charges of sexual conduct with a minor, incest and conspiracy.

Jeffs' Fundamentalist Church of Jesus Christ of Latter Day Saints bought the land near Eldorado four years ago and built the ranch, which they call the YFZ Ranch. The letters are said to refer to the words Yearning for Zion.

It is home to as many as 400 members who relocated from their Arizona and Utah compounds.

State and local law enforcement agencies set up roadblocks around the ranch Thursday evening, preventing journalists from seeing what was happening on the property, according to Randy Mankin, editor of the Eldorado Success weekly newspaper.

"This came totally out of the blue," Mankin said.

There were no indications of violence around the ranch, he said.

When CNN crews have visited the ranch, it was guarded by armed men equipped with night vision gear and other high-tech surveillance tools to prevent intruders.

When CNN flew over the ranch in a small plane last year, the crew saw a massive temple, the three-story housing units where Jeffs' chosen followers live, the water tower, the school and community center, the dairy and cheese factory and a massive concrete mill.

The church openly practices polygamy in two towns straddling the Arizona-Utah state line -- Hildale, Utah, and Colorado City, Arizona -- but members living on their Texas ranch rarely venture into Eldorado, four miles to the south.

Critics of the sect say that it arranges marriages for girls as young as 13 and that competition for brides may be reduced through exiling young men. If male followers are excommunicated, the critics claim, their wives and children can be reassigned to someone else.E-mail to a friend